Terque novas circum felix eat hostia fruges, Omnis quam chorus et socii comitentur ovantes Et Cererem clamore vocent in tecta ... give a charming picture of a lustratio of this kind, without enabling us to decide whether he has the farm or the pagus in his mind. Let us go on to the beginnings of the city, where we shall find the same principle and process applied in most striking fashion. Just as it was necessary to keep hostile spirits out of the homestead and its land, so it was necessary to keep them out of the city and its land. The walls of the Italian city were sacred, and so was a certain space outside them, called the _pomerium_. This is well illustrated in the rite used in the foundation of a city even in historical times, as described by Varro, Servius, and Plutarch:[123] it was believed to be of Etruscan origin, like so many other Roman rites, but it is now generally considered to be old Italian in a general sense. A white ox and a white cow were harnessed to a plough, of which the share must be made of bronze, and (on an auspicious day) drew a rectangular furrow where the walls of the city were to be: the earth was turned inwards to indicate the line of the wall, and the furrow represented the future pomerium. When the plough came to the place where there was to be a gate, it was lifted over it and the ploughing resumed beyond it. This meant that though the walls were sacred, the gates were profane; for, as Plutarch says, had the gates been holy, scruple would have been felt about the passage in and out of them of unholy things. The result of this religious process was to keep outside the sacred boundary of the wall all evil and strange spirits (or, as we may now say, seeing that we are entering an era of higher civilization, strange _gods_); and inside it there dwelt only those who belonged to the place and its inhabitants (_indigetes_), and whose alliance and protection had become assured. Inside it, too, and only within its limits, could the auspicia of the city be taken.